The effect of temperature on the development of Nephus includens (Kirsch) and Nephus bisignatus (Boheman) (Coleoptera: Coccinellidae), predators of Planococcus citri Risso (Hemiptera: Pseudococcidae)

The effect of temperature οη the development of the predators Nephus includens (Kirsch) and Ν. bisignatus (Boheman) (Coleoptera: Coccinellidae), was studied. The development time of immature stages and the pre-oviposition period of adult females for the two predators was recorded at eight constant temperatures (10, 15, 20, 25, 30, 32.5, 35 and 37.5°C). The beetles were reared on eggs, nymphs and female adults of Planococcus citri (Risso) (Homoptera: Pseudococcidae) that had developed on squash (Cucurbita pepo) and on sour orange leaves (CΊtrus aurantium). Using the linear model for the biological cycle of Ν. includens on squash and on sour orange leaves, the developmental zeros (lower temperature thresholds) were estimated to be 10.9 and 11.0°C respectively and the thermal constants, 490.5 and 472.8 day-degrees respectively. Using the Lactin model the lower thresholds were estimated to be 11.1 and 11.2°C respectively and the upper thresholds 36.1 and 36.0°C respectively. For the biological cycle of Ν. bisignatus, using the linear model, the lower thresholds were estimated to be 9.4°C on squash and 9.3°C on sour orange leaves and the thermal constants were 614.3 and 647.9 day-degrees respectively. Using the Lactin model the lower thresholds were estimated to be 9.9 and 1O.0°C respectively and the upper thresholds, 34.7 and 35.0°C respectively. The survival rate of Ν. includens in­stars at 10, 15, 20, 25, 30, 32.5, 35 and 37.5°C on squash and on sour orange leaves was respectively 0.0, 34.9, 63.2, 70.6, 63.3, 54.5, 19.8, 0.0, and 0.0, 32.2, 61.0, 68.0, 68.3, 56.6, 17.6, 0.0%. The survival rate of Ν. bisignatus instars at 10, 15, 20, 25, 30, 32.5 and 35°C on squash and on sour orange leaves was respectively, 0.0, 39.9, 61.1, 60.7, 47.2, 26.4, 0.0 and 0.0, 35.7, 65.7, 68.0, 44.2, 29.1, 0.0%. The results show that Ν. includens has a shorter biological cycle than Ν. bisignatus, whereas the latter species has lower temperature thresholds

Use of Lichen and Moss in Assessment of Forest Contamination with Heavy Metals in Praded and Glacensis Euroregions (Poland and Czech Republic)

The concentrations of selected metals—Cr, Ni, Cu, Zn, Cd, and Pb—were determined in the samples of Hypogymnia physodes lichen and Pleurozium schreberi moss collected in Polish and Czech Euroregions Praded and Glacensis. More specifically, the samples were collected in Bory Stobrawskie, Bory Niemodlińskie, and Kotlina Kłodzka (Poland) and in Jeseniki (Czech Republic). The concentration of metals in the samples was measured using the atomic absorption spectrometry (flame AAS technique and electrothermal atomization AAS technique). The results were used to calculate the comparison factor (CF) that quantifies the difference in concentration of a given bioavailable analyte × accumulated in lichens and mosses: CF = 2 (cx,lichen − cx,moss) (cx,lichen + cx,moss)−1. The values of CF greater than 0.62 indicate the most probable location of heavy metals deposited in the considered area. In this work, the method was used to show a significant contribution of urban emissions to the deposition of heavy metals in the area of Bory Stobrawskie and in the vicinity of Kłodzko City

New Species Of Paranthrene (Lepidoptera, Sesiidae)

Volume: 81Start Page: 499End Page: 50

Effects of Short- and Long-Day Photoperiods on Growth and Development of Sesamia nonagrioides (Lepidoptera: Noctuidae)

The effects of 2 photoperiods, a diapause-inducing (10:14 [L:D] h) and a non-diapause inducing one (16:8 [L:D] h) at 25°C on the growth and development of larvae of the corn stalk borer, Sesamia nonagrioides, were investigated. Under a long-day photoperiod, larvae completed their development and pupated after 6 molts, whereas under a diapause-inducing short-day photoperiod, several additional molts and considerable delay of pupation were recorded. Duration of 1st to 5th instars was about the same in diapause and nondiapause destined insects, but the duration of the 6th instar was significantly longer in diapause larvae. Similarly, head capsule widths of the larvae were about the same under both photoperiods until the 5th instar. The head capsule width of all instars, under both photoperiods, is described by the logistic model. Dyar's rule, implying a geometric model, was not found appropriate for our data. Larval weights were greater under long-day photoperiod up to 5th instar, but the reverse was true for 6th instar. Only 36% of the initial number of larvae reached pupation under short-day photoperiod, whereas 74% reached pupation under long-day photoperiod. Larval mortality gradually increased, for ≈ about 150 d under short-day photoperiod, whereas under long-day photoperiod, larval mortality occurred mainly during the first few days. Mean pupal weights for diapause and nondiapause insects were 202.8 mg and 168.1 mg, respectively. Under both photoperiods, female larvae tended to pupate later and the pupae were heavier

Diapause Termination in Sesamia nonagrioides (Lepidoptera: Noctuidae) under Laboratory and Field Conditions

The influence of photoperiod and temperature on the termination of diapause of Sesamia nonagrioides (Levebvre) was evaluated under laboratory and field conditions. Long-day photoperiod enhanced termination of diapause. Larvae held under a short-day photoperiod (10:14 [L:D] h) for various times and then transferred to a long-day photoperiod (16:8 [L:D] h) proceeded to pupate in ≈14 d, indicating that regardless of the state of diapause intensity, diapause completion and postdiapause development lasted similar lengths of time. Larval diapause termination was not hastened when diapausing larvae kept at a photoperiod of 10:14 (L:D) h and 25°C were exposed for short periods at 30, 35, and 40°C, whereas it was shortened when diapausing larvae were transferred from 25 to 30°C and kept continuously at this temperature. At higher temperatures (35 and 40°C), all transferred larvae died. It was also shown that exposure of diapausing larvae to low temperature (5°C) simply accelerated diapause development but termination of diapause did not require a period of chilling. Moreover, after low temperature treatment, diapausing larvae showed a faster diapause development when transferred to a long-day photoperiod than those kept in a short-day photoperiod. In the latter case, the longer the exposure the faster the termination occurred. Diapause termination of field-collected larvae was practically spontaneous. After transfer to laboratory conditions, 25°C and a photoperiod of 16:8 (L:D) h, they quickly proceeded to pupate. Field-diapausing larvae terminated diapause in January but exhibited a postdiapause development; the 1st record of pupation was observed in the field at the end of March

Distribuição espacial e plano de amostragem de Calacarus heveae (Acari) em seringueira Spatial distribution and sampling plan for Calacarus heveae (Acari) on rubber trees

Calacarus heveae Feres, 1992 é um eriofídeo descrito de espécimes coletados em plantas de seringueira (Hevea brasiliensis, Euphorbiaceae) na região noroeste do Estado de São Paulo. Esse ácaro prefere a face adaxial dos folíolos e pode causar a perda do brilho, amarelecimento, bronzeamento dessa região e a subseqüente queda prematura das folhas. O objetivo deste trabalho foi analisar a distribuição de C. heveae em seringueira, selecionar a unidade de amostragem mais representativa e desenvolver um plano de amostragem para o estudo de sua flutuação populacional. O trabalho foi conduzido com os clones PB 260 e IAN 873, respectivamente nos municípios de Itiquira e de Pontes e Lacerda, ambos no Mato Grosso. Em Itiquira, diferenças significativas foram observadas em quatro ocasiões em relação ao número médio de ácaros por folha nos diferentes estratos das plantas. Nas amostragens realizadas em Pontes e Lacerda, nenhuma diferença significativa foi encontrada entre os estratos em relação àquele parâmetro. Apenas em Itiquira, em uma ocasião de amostragem, foi verificada diferença entre os três estratos, em relação à proporção de folhas infestadas. Nenhuma diferença significativa foi verificada em relação ao número médio de ácaros por folha e proporção de folhas infestadas por C. heveae a diferentes distâncias da periferia da copa. Calacarus heveae exibe distribuição agregada no campo. Para estimar a densidade de C. heveae, um plano numérico e um plano binomial de amostragem foram desenvolvidos.<br>Calacarus heveae Feres, 1992 (Eriophyidae) is a mite described from specimens collected on rubber tree (Hevea brasiliensis, Euphorbiaceae) in the northwest region of the state of São Paulo. This mite prefers the adaxial face of the folioles which it can turn dry, yellowish and brownish; it can also cause leaf fall. The aim of this work was to analyze the distribution of C. heveae on rubber trees, to select the most representative sampling unit and to develop a sampling plan to determine the populational fluctuation. This study was conducted with clones PB 260 and IAN 873, in Itiquira and Pontes e Lacerda, respectively, both in the state of Mato Grosso. In Itiquira, significant differences were observed in four occasions in relation to the average number of mites per leaf in the different plant strata. In the samplings carried out in Pontes e Lacerda, no significant differences were observed between strata in relation to that parameter. Only in Itiquira, in one occasion, a significant difference between strata was verified in relation to the proportion of infested leaves. No significant differences were verified in relation to the average number of mites per leaf and proportion of leaves infested by C. heveae at different depths in the canopy. Calacarus heveae exhibits aggregated distribution in the field. To estimate the density of C. heveae, numeric and sampling plans were developed